Apparatus for kerfing blocks for printing



Dec.'25, 1934. E. F. TRETBAR, JR 1,985,302

APPARATUS FOR KRRFING BLOCKS ROR PRINTING Filed March 9, 1932 sheets-sheet 1 DCC 25, 1934- E. F. TRETBAR, JR

APPARATUS FOR KERFING BLOCKS FOR PRINTING 4 Sh 13S-Sheet 2 b @wm/ff Q .Ln n i um I] uw Dec 25, 1934- E. F. TKRETBAR, JR

APPARATUS FOR KERFING BLOCKS FOR PRINTING Filed March 9, 1932 4 Sheets-Sheet I5 Dec 25, 1934. E. F. TRETBAR, JR

` APPARATS FOR KERFING' BLOCKS FOR PRINTING 4 sheetssheet 4 Filed March 9, 1932 Patented Dec. 25, 1934 UNITED n STATES lanterne. BLOCKS Fonl PRINTING y APPARATUS FOR PATENT oi-Flor: d

Edward F.`Tretbar, Jr., Camden, N. J. Application March 9, 1932, serial No. 597,661 i A1to1-aims. (01. MA1- 133i My invention is an improved machine for kerng blocks and rendering them suitable forv lo from exactly 4the same distance as the .spacingv between the kerfsv of either set thereto. v

A further object of my invention is the provior in. proportion sion of means for cutting kerfs at any desired may be effected either in accordance-With the' metric system or in accordance with the.So--

called English or fractional inch system.

A series of saws are adjustably mounted upon a series of brackets supported byA a carriage reciprocable transversely to the work supporting carriage, the carriage preferably being driven by a shaftto which power is applied intermediate, its ends froma motor mounted at 'oneend of theL saw carriage. The reciprocations of the saw carriage control the actuations ofthe torque motor by'which :the step by step movement .is

given the carriage supporting work table; such step by stepr movements being given after each 40 complete reciprocation of the saw carriage.

The characteristics and advantages of my improved apparatus will-further appear from the following description and the accompanying drawings of apreferred embodiment of my im;

provements.

In the drawingsFig. l `is a part sectional side elevation of a kerng machine 'embodying my improvements; Fig.-2 is an enlarged fragmentary detail on the line 2-2 off-Fig. 1; Fig. 3 is an enlarged fragmentary sectional view showing clamping means for securing the rotary work tableagainst rotation on its carriage; Fig. 4 is an end View of the machine shown in Fig. l; Fig. 5 is anenlarged front elevationof one of the saw units; Fig. Sis a diagi'ammaticsiwring.

diagram by ,which the operations` of the worky carriage .and saw carriage are controlled and correlated; Fig. 7 is an enlarged-elevation offmechanism for `effecting ,step by step movement of the work carriage; Fig. 8 is a fragmentary sectionalfviewrontheline 8.-,-8 of` Fig. 7^; Figfa is a fragmentary sectional view;on the line 97-9' of Fig. 7; Fig. lil-is an enlarged detached end elevation of` mechanism used in reciprocating the saw carriage; Fig. 11- is a` transverse sectional viewon the line 11,-11 of Fig. 10 Fig. l2 .is va transverse sectional view on the line 12-,12of

Fig. 10, and Fig. 13 is a top plan viewvof the mechanism shown in Fig. 10 and Fig. 14 is a fragmentary section of a printing block kerfed by my improved machine. p f Y As illustrated inthe drawings, a frame l hasy longitudinal beams 2 4 which support V-shaped rails 3 forming slideways for a reciprocable carriage Aor table 4. The carriage 41contains a recessed portion 5 in which is mounted av ring 6 normally supported by: springs r'l by which the table is biased toward its upward position. Bolts 8 are connected with the ring G'and extend through certain ofthe springs `and through the web 9 of the carriage 4. (Figs. l and'4.) Lock nuts l xed on` the respective bolts limit the upward movement ofthe ring 6 while permitting movement `thereof downward by compressing; the springs 'l'. y

The` ring 6 contains `a circular raceway 11 for the antifriction `balls 12 which engage a complementary groove or raceway 13 in a table 14 adapted to rotate "over 4the carriage 4.` Clamps 15 are supportedfon bolts 16 and-nuts 16a (Figs. 1 and 3) depending from depressed portions 17 in theV periphery of the revoluble table 14. Theclamps 15 have projecting lips 18 adaptedto engage beneath a flange 19 of the reciprocating 'carriage 4 so that by rotating'the nuts 16a and drawing the lips 18 tightly against the flange v1,9.the'rotary ta-` ble may be locked against rotary movement on its pivot or center'pin `20 Acarried the reciprocatl l ingcarriage 4. Y v

The sliding carriage 4 is reciprocable step by step by means of a worm or leadscrew 21' (Figs.

l, 2, `4, 9) having cylindrical ends journalled in bearings 22`ancl 23. A bronze nut'24 is xed to the table 4 andcontains a thread .complementary to the thread on the leadscrew 21 which passes through the nut and by its rotation reciprocates the table 4. -f' The lead screw is rotated a distance suiiicientf to effect a desired'longitudinal movement of the table 4pby means of registering mechanism.. vconnected therewith. This registering mechanism is preferably adjustable to eect movements of the lead screw and consequently movements of the reciprocable table either in accordance with the metric system or the so-called English system of measurements by fractions of an inch.

The registering mechanism (Figs. 1, 4, 7, 8, 9) consists of a gear 25 fixed to the screw 21 and meshing with a gear 26 revoluble on a stub shaft 27 for communicating a step by step movement when feeding of the table in accordance with the metric system is desired. When it is desired to feed the table `in accordance with the so-called English system, a ratchet 28 is fixed to the shaft 21 and has its teeth 29 engaged by a dog 30 pivoted on a pintle 31 carried by the triangular arm 32 having a hub 33 loosely sleeved on a collar or hub of the ratchet 28. The arm 32 is pivotally connected through the link 34 with a fulcrummed arm 35 (Figs. 7, 8, 9) depending from the pivot 36 fixed on the frame.v The lower end of the lever 35 contains a slot 36 in which is engaged a slide 37 carried by a split eccentric bar 38 adjustably fixed to the shaft 39 of a gear 40 meshing with a pinion 41.

The pinion 41 (Figs. 7, 8) is operated through a spring 42 by a torque motor 43 when the circuit thereof is closed as hereinafter described. A cable 44, wrapped around a sheave 45 and connected with the counterweight 46, restores the mechanism to its initial position after each operation of the torque motor.

When it is desired to operated the carriage in accordance with the metric system, the ratchet 28 and arm 32 are removed from the end of the work 21 and journalled upon the collar 26 (Fig. 9) of the gear 26 and splined Vrelatively thereto so that instead of the ratchet lmechanism acting directly upon the screw 21 it acts through the gears 26 and 25. It will be understood that by providing ratchets having different numbers of teeth and suitably adjusting the eccentric 37, the distance travelled by the reciprocable table 4 at each operation of the torque motor 43 may be varied as desired when using either the metric system or English system of measurements.

A saw carriage 47 (Figs. l, 4) is reciprocable on the grooved rails 48 carried by the top of the frame l and moves in a direction transverse to the direction of movement of the carriage 4.

A reversible motor 49 mounted on the carriage 47 has its shaft connected by a coupling 50 with transmission mechanism contained in a housing and comprising a shaft 51 (Figs. 10, 12, 13) having fixed thereto a clutch cup 52 complementary to the spring pressed clutch cone 53 splined on thesleeve 54. The sleeve 54 has formed thereon a pinion 55 which meshes with a gear wheel 56 fixed on the shaft 57 (Fig. 13). A pinion 58, fixed to the shaft 57, meshes with a gear 59 fixed to the shaft 60, on which shaft is also mounted a pinion 61 meshing with a gear 62yjournalled on the sleeve 63 (Fig. 11). The hub of the gear 62 is provided with clutch jaws 64 adapted to coact with jaws of a clutch sleeve 65 splined on the sleeve shaft 66 which is secured by a coupling 67 (Fig. 1) to the shaft 68. Pinions 69 and 70 are xed to the shaft 68 and mesh with the teeth of the racks 7l and 72 carried by the frame and reciprocate the'carriage 47 backward and forward.

The carriage 47 may be operated manually by means of a pinion 73'(Figs. 10, 12) meshing with the gear 59 and having its shaft 74 projecting from the transmission housing and provided with a hexagonal end 75 for the attachment of a suitable handle.

The reciprocation of the carriage 47 by the motor 49 is controlled (Figs. 1, 4) by a reciprocable bar 76 mounted in suitable brackets 77 on the frame adjacent to the transmission housing and containing a series of apertures for the attachment of stops 78 and 79 at desired points along the length of the bar 76. A stud or finger 80 (Fig. l) depending from the transmission housing substantially in line with the axis of the saws hereinafter described shifts the bar 76 by engagement with the stops 78 and 79, which are so positioned as to regulate the length of the desired travel of the carriage 47.

The bar 76 has connected therewith an arm 81 adapted for engaging the yoke arms 82 and 83 projecting from a handle 84 of a master switch 85. This master switch 85 has spring switch blades 86 and 87 (Fig. 6) connected with a negative terminal 88 of a cut-out switch 89 and a spring switch blade 90 connected with a negative terminal 91 of the cut-out switch 89. The spring switch blades are operable through a suitable cam 92 by the handle 84 to control the flow of current to thetorque motor 43 through the limit switch 93 (Fig. 4) operated by the iiange 95 on the transmission housing, and to the reversing motor 49 controlled by contactors 96 and 97 of standard construction. The circuits are completed by suitable conductors connected with the terminal 98 of the cut-out switch 89.

When the carriage 47 is traveling toward the left (Fig. 4), the switch blade 86 is in contact with the terminal 86', and the switch blade 90 is in contact with the'terminal 90', but iiow of current through the torque motor 43 during the greater part of the travel of the carriage toward the left is prevented by the open limit switch 93, the latter being automatically opened upon the disengagement thereof by the flange 95. The switch 87 is in contact with the terminal 87', which permits the flow of current through the contactor mechanisms to cause the contactor 97 to pass current to the motor 49 in a direction causing the continued movement of the carriage to the left.;

When the pin 80 on the transmission casing engages the stop 78 to shift the rod 76 and throw the handle 84 of the master switch, the blades 86 and 90 (Fig. 6) are disengaged from the contacts 86 and 90', and the switch blade 87 is disengaged from the terminal 87 and engaged with the terminal 87". In this position of the switch, no current can ow through the torque motor even when the limit switch 93 is closed by the flange 95, but current is supplied to the motor 49 through the contactor 96 to continue the rotation of the motor 49 in a direction causing the movement of the carriage 47 to the right. As the carriage 47 approaches the right hand limit of movement, (Fig. 4) the 11a-nge 95 engages an arm of the limit switch 93 and closes the contacts thereof a short time before the master switch 85 is thrown by the engagement of the finger 80 with the right hand stop 79. As soon as the master switch is thrown by the engagement of the finger 80 with the stop 79, the contacts 86 and 90 engage the contacts 86 and 99', and as the limit switch 93 is at this time closed by the flange 95, current is supplied to the torque motor 43 to cause one revolution vthereof and advance the registering mechanism and work table one step through the mechanism previously described. Simultaneously with the operation of the torque y motor, the blade 87 `is disengaged :from ,the .con-

' antifriction bearings 112 tact 87"' and reengaged with the contact 87 to reverse the motor 49 and again start it rotat- 47 toward thezleft.

' The beams of the carriage 47 have mountedv thereon a, plurality of saw units eachiFig. 5) comprising a bracket or head 99 which is adjustable along the beams by a micrometer adjustment 100 (Fig. 1) and may be clamped in desired position by bolts 101 passing throughslightly elongated slots in the franges 99 of the brackets or heads 99. Each bracket has mounted thereon a slide 102 movable in guides in the heads 99 and vertically adjustable by means of a screw 103 journalled in the bracket and threaded in the slide. The screw is provided with a hand wheel 104 and with a graduated dial 105 coacting with a suitableindicator on the head to indicate the elevation of the slide. When the slide has been adjusted to a desired elevationitis clamped in place by bolts 106 passing through elongated slots in the' slide and threaded into the head.' The.

slide carries a motor 107 (Fig. 1), and a pulley 10S on the motor shaft is connected by a belt 109 with a pulley 110 fixed to the spindle 111 journalled in switches for the respective motors so that they,

may be concurrently or individually controlled.

From the foregoing description it will be un-` derstood that in kerng ya printing block such as is illustrated by way of example in Fig. 14, the block is secured to a holder which is rmly attached to the table 14. The table is then rotated on its axis to position the block at a desired angle to the planes of the cutters or saws 113, which are preferably of relatively small diameter. When the reversible table 14 has been so positioned theV nuts 16a on the bolts 16 are drawn up so as to clamp the lips 18 of the jaws 15 against the ange 19 ofthe reciprocating carriage 4 so as to lock the table 14 against rotary movement.

The carriage 4 is then moved on its rails 3 to the extreme right hand position (Fig. l.) by rotating the Worm or lead screw 21 by attaching a suitable handle vto the squared end of the lead screw. Should there be any variation in the distances of the .saws 113 from one another, the brackets 99 are adjusted by means of the micrometer adjustments 100 so that when the kerng is completed the last lrerf of one saw will register with the iirst kerf of the next saw or be spaced therefrom a distance exactly equal or proportionate to the spacing between the kerfs made by any one saw.

The depth of the cut to be made by the saws is regulated by adjusting the slides 102 vertically by means of the hand wheels 104 and then clamping the slides in position.

When current is turned on the motor 49 acts through the mechanism described to translate the carriage 47 (Fig. 4) while the saws 113 are cutting parallel kerfs across the block. When the carriage 47 has moved the desired distance, which has been predetermined by the positioning of the stops 78 and 79, the master switch 85 is thrown as previously described and the movement of the carriage 47 is reversed to carry depending 'from the v the saws vback through `the kerfs which they have just cut and clearrany detritus therefrom.

f When Ythe Jcarriage 47 again arrives at its startingv position .and before it begins a second movement, the torque `motorli revolves and acts through the mechanism described to causek the pawl 30 to advance the ratchet 29 onenotch, thereby rotating the .shaft 21 a desired distance to move the carriage forward one step as a resuit of the engagement of the shaft thread with the nut 24 on the carriage. A series of ratchets 28 may be provided having diierent numbers of teeth By the use of a ratchet having a desired number of teeth, any desired movement of the carriage 4 may vbe effected. The same set of ratchets may be Aused to give diiierent spacings by sleeving them on the hub 26 to give metric measurements, or by adjusting the throw of the lcranks to give fractional parts of the measurement for which the ratchet is designed.

The reciprocation of thev carriage 47 and the step `by step movement of the carriage 4 isconof kei-fs at any desired angle to the series of v kerfs `iirst cut without vremoving the block from the table.

My improved apparatus While .of general utility particularly adapted for keriing printing blocks `on'which a series of duplicate designs are formed .in relief before keriing and the character of the cutting tool may be variedwith the variations in the character or composition of the block to be cut.

Having described my invention, I claim:

1. In apparatus of the character described, a work table, means for moving said work table step by step and'cornprising a pawl and ratchet mechanism, a fulcrumed lever connected with sa'd pawl and ratchet mechanism, a crank adjustably. connected with said lever, and a motor for operating said crank, the motor being affected by means moving its movable element op,- positely to the movement of the element by its controlled motor-actuating force.

2. 1n apparatus of the character described, a work table, means for moving said worktable step by step and comprising a screw, pawl and ratchet mechanism kconnected with said screw, a fulcrumed levsr connected with said pawl' and ratchet mechanism, a motor to rock said pawl and ratchet mechanism in one direction' and means for actuating the motor and rockng said pawl and ratchet mechanism in a reverse direction and resetting said torque motor in a position for actuation.

3. In apparatus of the character described, a work holder, a'saw carriage reciprocable across the top of said work holder, a plurality of uniformly spaced cutters supportedby said saw carriage, means for reciprocating said saw carriage, and means for automatically advancing said work holder when said cutters are disengaged from work on said work holder to a position to eiect a new series of cuts spaced from the 'cuts ci a previously cut series by the distance of the work-carriage step. y

4. In apparatus ofthe character described, a work carriage, means for moving said carriage step by step, a work tablerotatable on said carriage, a saw carriage reciprooable transversely to the direction of movement of said work lcarriage, a plurality of uniformly spaced cutters carried by said saw carriage, means for adjusting the elevation of said cutters on said saw carriage, motor mechanism for reciprocating said saw carriage, separate motor mechanism for moving Ysaid work carriage step by step, switching mechanism operable by said saw carriage at each limit of its movement for controlling both` of said motor mechanisms and switching mechanism operable by said saw carriage at only one limit o its movement for further controlling said second named motor mechanism.

5. A keriing machine comprising a base, a turnable work support reciprocably diametrally mov.- able on said base, a cutter support reciprocably movable on said base across and at right angles to the path of reciprocable movement or said work support, a series of rotatable cutters on said cutter support for equal relative spacing and adjustable toward and away from said work support, means for actuating said cutter support, and means automatically responsive to actuation of said cutter support for actuating said work support to another cutting position whereby said cutters cut a new series of kerfs in which an end kerf is spaced from an end kerf of a previous series equal to a space between adjacent kerfs of a series.

6. In apparatus of the character described, a carriage, a plurality of spaced rotary cutters, means for reciprocating said cutters relatively to, and across the top of, said carriage, and means for advancing said carriage by steps equal to a division o the space between the cutters, and between the reciprocations, of said cutters.

7. In apparatus of the character described, a work carriage, means for eiecting step-by-step movement of said work carriage and comprising a screw, a saw carriage reciprocable across the.

top of, and transversely to the direction of movement of, said work carriage, a plurality of spaced saws, and means controlled by the reciprocation of said carriage for giving a step-by-step movement to said screw for moving the work carriage a distance constituting a divisor of the spacing between said saws.

3. The combination with a work carriage and means for moving the carriage step-by-step including a screw, a gear fixed to the screw, a second gear meshing with said first gear, a reverseiy movable drive element, and means including a pawl-and-ratchet device selectively connectible between either of said gears and said drive element.

9. A cutting machine comprising work and cutter supports, a plurality of equally-spaced cutters on the cutter support, means for eiecting relative cutting movement between said supports, and means for actuating said work support and controlling it to move a distance equal to a diA vision of the space between successive cutters directly to a new position for eecting a subse-v quent series of cuts parallel to the cuts of said first cutting movement.

1G. A cutting machine comprising work and cutter supports, a plurality of cutters on the cut-v ter support, means for eiecting relative cutting movement between said supports, and means controlledito directly move the supports relatively by a distance equal to a division of the space between successive cutters to a new position for effecting subsequent cuts.

1l. In combination, a movable work carriage, a cutter carriage reciprocably movable across the path thereof, spaced cutters on the cutter car-4 riage, means `for moving the work carriage and successively moving the cutters relative to cuts previously made by a distance equal to a division of the space between the cutters, said means comprising a screw, a ratchet mechanism connected to the screw and a motor including means biasing its movable element oppositely to movement eifected by its actuating force, and means operable by the reciprocations of the cutter carriage controiling said actuating force.

i2. In combination, a movable work carriage, a cutter carriage reciprocably movable across the path thereof, spaced cutters on the cutter carriage, means for moving the work carriage and eiecting a new position of one of the cutters relative to the work offset from a cut previously made by a distance equal to a division of the space between the cutters, said means comprising an electric motor, a switch controlling a circuit of the motor, means comprising an electric motor i'or reciprocating the cutter carriage, a switching mechanism operable by the reciprocations of the carriage for controlling the circuits of said motors, and a switch controlling the circuit of said first motor during a portion only of movement of the cutter carriage.

r13. A cutting machine comprising work and cutter supports, cutting means on said cutter support capable of effecting spaced cuts, and means responsive to relative movement of the supports for effecting relative movement between the supports by a distance equal to a division of the space between said spaced cuts.

14. A cutting machine comprising work and cutter supports, cutting means on said cutter support capable of eiecting cuts spaced a given distance apart, and means responsive to relative movement of the supports for eiecting relative movement between the supports by a given distance, one of said distances being equal to a division of the other.

EDWARD F. TRETBAR, J R. 

